Ground-surface adaption device for attachments on harvesting machines

ABSTRACT

A crop harvesting machine is provided having a crop feeder device that is movable through various heights via manipulation of first hydraulic cylinders. A crop gathering attachment is mounted onto a front side of the crop feeder device. A crop gathering attachment is provided having fixed height sensors that measure a distance of the attachment above the ground. A second hydraulic cylinder is provided between the crop feeder device and the crop gathering attachment to control the angle of tilt of the crop gathering attachment relative to the crop feeder device. The angle of tilt is measured by a tilt sensor. A controller is connected to the sensors and provides output to the cylinders to control the machine height and angle of tilt.

BACKGROUND OF THE INVENTION

The invention concerns a device for ground copying for front attachmentsto harvesting machines, especially for self-propelled combine harvestersand forage choppers, in accordance with the features in the genericterms of claim 1.

Such devices for ground copying serve to adjust the front attachments tothe unevenness of the ground, so that the crop can be harvested withoutloss even under these conditions. For this it is adequately known to fixthe attachments to the harvesting machine so that they can swivel, sothat on the one hand the so-called longitudinal movement of copying canbe executed along the axis transverse to the direction of travel of themachine and on the other hand transverse copying can be effected alongan axis pointing in the direction of travel. The cases for theapplication of such devices for ground copying extend to cutting andmowing machines of all types of construction and to gathering devices onthe most varied types of harvesting machines. Therefore they have becomeso important, as all these attachments must have an appropriately wideworking width because of the very high productive capacity of thepresent-day harvesting machines. In the state of the art a multitude ofvariant embodiments for this have already become known, which can bedivided into two large categories.

The first category is described in EP 0 331 893 B1, in which theattachment is fixed on the front side of the harvesting machine so thatit can tilt for the purpose of copying longitudinally and transversely.Two hydraulic cylinders arranged at a distance from each other andsymmetrically about the central longitudinal axis of the harvestingmachine support the attachment from below with a force such that ispresses on the ground only with a residual weight and consequently witha slight pressure, in order to be able to follow the irregularities ofthe ground via skates, running wheels or its ground trough itself forlongitudinal copying. For keeping to a set value for the ground pressureeither by means of suitable sensors, the pressure in the hydrauliccylinders or the supporting force of the hydraulic cylinders on thechassis of the harvesting machine is monitored. In the event of adeviation from this set value the piston rods of the hydraulic cylindersare driven so far in or out until the set value again prevails, which isassociated with a raising or lowering of the attachment. For transversecopying the attachment is equipped in its outer side regions with sprungelastic slide hoops, which detect the ground and via a potentiometerconnected to them furnish a measure of the distance of the attachmentfrom the ground. If the signals from both sides differ from each other,two further hydraulic cylinders have pressure applied to them, which areapplied in a vertical direction between for example the feeder shaft ofthe combine harvester and the attachment, which tilt the attachmentlaterally until on both sides of the attachment the same distance isrestored again.

Such devices for ground copying serve to adjust the front attachments tothe unevenness of the ground, so that the crop can be harvested withoutloss even under these conditions. For this it is adequately known to fixthe attachments to the harvesting machine so that they can swivel, sothat on the one hand the so-called longitudinal movement of copying canbe executed along the axis transverse to the direction of travel of themachine and on the other hand transverse copying can be effected alongan axis pointing in the direction of travel. The cases for theapplication of such devices for ground copying extend to cutting andmowing machines of all types of construction and to gathering devices onthe most varied types of harvesting machines. Therefore they have becomeso important, as all these attachments must have an appropriately wideworking width because of the very high productive capacity of thepresent-day harvesting machines. In the state of the art a multitude ofvariant embodiments for this have already become known, which can bedivided into two large categories.

As regards this device for ground copying, it can be criticized on theone hand since because of the constantly flowing hydraulic oil it reactsto a considerable degree much too sluggishly. On the other hand itdelivers the control signal for longitudinal copying much too late.Furthermore there is a disadvantage that through ground detection underdifferent weather conditions, through constantly changing leverageratios and hysteresis phenomena in the lifting system and through theinfluence of markedly fluctuating dynamic forces, practically noreproducible set values for ground pressure can be realized. Theconsequence of this is that obstacles cannot be avoided and itsoperability is put into question even at moderate driving speeds.

The second category of devices for ground copying, one embodiment ofwhich is described in EP 0 748 153 B1, works alongside the facilityproposed in the first category via direct ground contact of theattachment now principally without this. For this, ultrasound sensorsare fixed on both sides in the region of its sidewalls, whichcontinuously measure the distance of the attachment from the ground andproduce a corresponding output signal. In the driver's cab of thisharvester a control device is installed, which receives the outputsignals from the ultrasound sensors and in the event of a deviation froma prescribed set value for the distance it addresses a control valve inthe hydraulic circuit of the hydraulic cylinder for raising and loweringthe attachment. Since the hydraulic cylinder is arranged analogously tothe solution described in the foregoing and is actuated likewise, thissystem operates just as sluggishly and imprecisely as regards adherenceto the set value for the distance between the attachment and the ground.The ultrasound sensors present an additional disturbing factor, as theycannot distinguish between plants or stubble lying on the ground and theground itself, so that under these conditions they deliver falsedistances. Because of their arrangement just above the ground, theseerrors are made especially noticeable. Furthermore, ultrasound sensorsreact to wind and humidity with a large scattering of the measuredvalues. In addition they are relatively expensive to purchase, so thatall these disadvantages taken together could be the reason that such adevice for ground copying has not been accepted in practice.

Setting out from the negative experiences from the afore-describedsolution, a further device for ground copying has been published in EP 0511 768 B1 and EP 0 936 475 A1, where the ultrasound sensors employedthere are fixed far above the ground and in the side region of theattachments. With this it is achieved that only the measurement errorfor distance caused by stubble or plants lying on the ground isdiminished somewhat as a percentage.

A further possibility for a device for ground copying be means ofultrasound sensors is described in EP 0 765 594 A1 with an example of acombine harvester cutter. There the ultrasound sensors measurecontinuously the distance to the sensor skids attached to the exteriorof the cutter with the aid of a plate attached to them, in order toexclude the error from ground sensing. However this measure alone is notsufficient for well-functioning ground copying. Furthermore, the angleof incidence and emission to the plate varies constantly, so thatdistortions to the measurement of distance occur.

To be assessed analogously is the ground copying in accordance with DE196 01 420 A1, where a prestressed sliding element of narrow springsteel senses the ground and transmits its movement in consequence ofground irregularities to a signal transmission element. This is formedas a parallelogram of rods, to which a plate is attached, which incontrast to the previously described plate on the sensor skid executesapproximately parallel movements. This is irradiated by a wave sensorand reflects its radiation. From this the wave sensor determines ameasure for the change in position of the sliding element, which is in adirectly proportional ratio to the distance of the attachment from theground. The measure thus determined with a somewhat greater accuracy, ishowever used finally also only for driving a control valve in thehydraulic circuit for the hydraulic cylinder for raising and loweringthe front attachment, so that all the previously mentioned disadvantagescannot be removed even with this ground copying. An additionaldeficiency is caused be the narrow sliding elements in the presence oflongitudinal grooves in the ground, as they then indicate a falsedistance.

BRIEF SUMMARY OF THE INVENTION

Therefore the objective of the invention is to create a device forground copying for front attachments to harvesting machines, whichreacts rapidly to irregularities in the ground, even at higher drivingspeeds, which adheres with greater precision to the distance of theattachment from the ground, which is prescribed as the set value, andwhich is manufacturable economically.

This objective is solved according to the invention by the features ofthe 1^(st) claim, in which the features are listed in the subclaims,which further develop this solution in an advantageous manner.

Through the attachment of the feeder device to the harvesting machine bymeans of powerful hydraulic cylinders so that its height can be altered,it is possible to tilt this, together with the attachment fixed to thefront, through a relatively large range, which is used superficially foradjusting the starting position of the attachment for proper use andraising it to a transport position. Because of the size of thishydraulic cylinder and the flow of large quantities of hydraulic oilassociated with it this movement takes quite a long time. Therefore forthe purpose of longitudinal copying on the ground, the attachment isfixed to the feeder device so that it can tilt on an axle alignedtransversely to the direction of travel of travel of the harvestingmachine, so that it can move relative to the fixed feeder device about adefined angle of tilt. For monitoring the defined range for the angle oftilt, a sensor is arranged in a fixed position on the feeder device,which is in contact with the attachment. For the enforced movement ofthe attachment within the defined range, according to the inventionbetween it and the feeder device a relatively smaller, and hence fastreacting hydraulic working cylinder, is envisaged.

On the attachment there is at feast one further sensor, which constantlymeasures the distance of the attachment from the ground. Both sensorsfurnish electrical signals, which are passed on to a controller, whichcan influence the hydraulic system of the hydraulic cylinder beneathfeeder device and that of the hydraulic working cylinder between thefeeder device and the front attachment.

A more expedient embodiment of the device for ground copying inaccordance with the invention consists in that the distance of theattachment from the ground is determined by feelers sliding along theground and which are moveable as regards height relative to theattachment, which transmit their height movement proportionally toso-called angular sensors for producing an appropriate output voltage.In the case of the use of a cutter as an attachment, it is suggested touse as a feeler just the stem divider located in the region of thesidewalls plainly front of the cutter bar.

In a further advantageous embodiment of the invention it has proved itsworth, to suspend the attachment on the feeder device so as to becapable additionally of tilting about an axis pointing in the directionof travel of the harvesting machine for the purpose of transversecopying. A further hydraulic cylinder arranged accordingly between thefeeder device and the attachment is likewise connected to thecontroller, which for its operation utilizes the signals from thesensors for measuring the distance.

The method of functioning of the device for ground copying begins thus,in that a preselection of the mode of operation of the attachment ismade through an operating element located in the driver's cab of theharvesting machine, in which the pushbutton for “ground copying” ispressed. Thus the controller designed as a software controller forexecuting the necessary control and computing operations for groundcopying is activated. Then a set-value transmitter is adjusted to thedesired set distance of the attachment from the ground, which isconveyed to the controller via its input lead. Also the left and righthand sensors in the stem divider, which continually determine the actualdistance of the attachment from the ground, deliver their values and thesensor for monitoring the defined range for the angle of tilt likewisedelivers its value to the controller via separate input leads.

As long as the front attachment is in the transport position or is onthe way to its starting position for field use, the two actual distancesare greater than the set-value for distance and the controller lowersthe feeder device together with the attachment in the direction of theground. Previously or simultaneously via the hydraulic working cylinderit sets the attachment to the mean value of the defined range for theangle of tilt, the attainment of which is signaled by the sensor betweenthe feeder device and the attachment. Incidentally, so that theattachment when longitudinal copying can follow all ordinarily largebumps and dips in the ground within the defined range for the angle oftilt, it has proved expedient to permit for this about a 10-degree rangeof freedom. The starting position of the attachment for field use isthen reached, if the two actual distances or the average value foractual distance calculated by the controller agree with the set-valuefor distance, and hydraulic cylinders thereupon stop the loweringmovement of the feeder device.

The longitudinal copying in field use over above averagely large bumpsand dips in the ground is executed by the hydraulic working cylinderalone, as long as the angle of tilt lies within its defined range. Forthis the controller compares the mean actual distance of the attachmentfrom the ground and accordingly controls magnitude of the deviation ofthe hydraulic working cylinder to a length for immediate readjustment tothe set distance. If the attachment encounters above averagely largebumps and depressions in the ground, the angle of tilt attains the upperor lower limit of the defined range. This is reported by the sensor formonitoring the angle of tilt to the controller, which thereupon raisesor lowers the feeder device via its hydraulic cylinders so far, untilthe angle of tilt is again within its defined range. At the same timethey hydraulic working cylinder likewise via the control signals fromthe controller takes care of adherence to the set-value for distance.

In a further preferred variant embodiment of the invention, thelongitudinal copying according to the invention is advantageouslycombined with simultaneous transverse copying, in which the controllertransmits to the hydraulic cylinder a control signal from the differencein the actual distance, which tilts the attachment about an axis whichpoints along the direction of travel of the harvesting machine.

To sum up, the advantages of the invention are that with it very rapidground copying has become possible for the front attachment of aharvesting machine, which shows itself particularly at high travelingspeeds of the harvesting machine. The sensors which measure the distanceof the attachment from the ground in the embodiment of mechanicalfeelers in conjunction with angular sensors delivering electricalsignals furnish the most precise values, so that the attachment canfollow the ground contour exactly. Finally, for this device for groundcopying only simple components, which are already present on harvestingmachines, are necessary so that their costs of manufacture are keptwithin limits.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained in more detail using one example ofits embodiment, in which the individual figures show:

FIG. 1 is a side view of the front part of a schematically depictedcombine harvester with a feeder shaft and cutter;

FIG. 2 is an enlarged section of the lower part of the tilting framefrom FIG. 1; and

FIG. 3 is an electrical/hydraulic circuit diagram of the device forground copying.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In FIGS. 1 and 2 the device for ground copying is realized with anexample of a combine harvester, which possesses a feeder shaft as afeeder device 1 for the material to be threshed, which is fixed on thechassis 3 around its upper shaft axle 2 so that it can be tilted toadjust its height. For this there are between the chassis 3 and theunder side of the feeder shaft two hydraulic cylinders 5 fixed one oneach side which act on it through articulated joints 4 and 4′. At thefront the feeder shaft is equipped with reinforcing frames 6, on theunder side of which there is an axle 7 which runs transversely to thedirection of travel of the combine harvester. Around this axle 7 isarranged a tilting frame 8 opposite the reinforcing frame 6 so that itcan tilt through a defined angle of tilt 9. A hydraulic working cylinder10, which is joined with articulated joints at one end to the upper sideof the feeder shaft and at the other end to the tilting frame 8 formsthe connection, which changes the distance between them. A sensor 11attached to the side of the feeder shaft with its feeler arm 12 touchingthe tilting frame 8 constantly records the magnitude of the angle oftilt 9.

Besides the tilting frame 8 is suspended opposite the reinforcing frame6 so that it can tilt about an axle 13 pointing in the direction oftravel of the combine harvester, for which between the feeder shaft andthe tilting frame 8 a hydraulic cylinder 14 with articulated joints isarranged vertically on the left side viewed in the direction of travel.

The tilting frame 8 is designed so that it can rapidly pick up a frontattachment 15 for the harvesting machine and deposit again on the groundor a transport lorry, which in this example is a cutter. When groundcopying, its cutter bar 16 exhibits a distance 17 from the ground, whichis measured constantly on both sides of the attachment 15 with a sensor18 on each side. The sensors 18 which are designed as angular sensorsare coupled for this with the stem dividers 19 of the attachment 15,which are adjustable in height and slide on the ground, are coupled insuch a manner that their movement in height is transferableproportionally to the tilting movement of the sensors 18.

The electrical/hydraulic circuit diagram of FIG. 3 conveys an overviewof all the control and operating elements necessary for ground copyingand of their interaction in the circuit. For this the harvesting machineis equipped at a suitable place with a hydraulic variable displacementpump 20, which is connected with a hydraulic positioning device 21. Itssuction pipe 22 and overflow oil pipe 23 and the return flow pipe 24 ofthe entire hydraulic system end together in the hydraulic oil reservoir25. Its pressure pipe 26 is connected on the one hand via a currentregulator for lifting 27 and a logic element 28 with the hydrauliccylinders 5 beneath the feeder shaft. On the other hand there is aconnection between the hydraulic cylinders 5 and the return flow pipe 24via the logic element 28 and an electrical shut-off valve 29 as well asa current controller for lowering 30.

On the other hand, the pressure pipe 26 is connected via a 4/3-wayproportional valve 31 and a simple lowering brake valve 32 with thehydraulic working cylinder 10 for longitudinal copying and in additionvia another 4/3-way proportional valve 33 and a double lowering brakevalve 34 with the hydraulic cylinder for transverse copying.

To the electrical part of ground copying belongs an operating unit 35for preselecting the options for employment of the attachment 15, forwhich a pushbutton 36 for manual control, a pushbutton 37 for highcutting, a pushbutton 38 for regulation of supporting pressure andfinally a pushbutton 39 for ground copying of the attachment 15 areavailable. The operating unit 35 is connected with a controller 40,which is designed as a software controller for executing control andcomputing operations. It gets via an input lead 41 from a set valuetransmitter 42 the default value for a set distance measure 17 for theattachment 15 from the ground, via the input leads 43;43′ the actualdistance 17 from the sensors 18 and via input lead 44 from sensor 11 theactual value for the angle of tilt 9. For outputting its control signalsit possesses output leads 45;45′ leading to the current regulator forraising 27 and to the current regulator for lowering 30 respectively,for the hydraulic cylinder 5, an output lead to the electrical shut-offvalve 29, output leads 47;47′ to the 4/3-way proportional valve 31 forthe hydraulic working cylinder 10 and output leads 48;48′ to the 4/3-wayproportional valve 33 for the hydraulic cylinder 14.

Furthermore, the controller 40 is connected with a hand lever 49, fromwhich it receives control signals for manual control of the frontattachment 15.

What is claimed is:
 1. In a crop harvesting machine movable along adirection of travel and having a crop feeder device movable throughvariable heights above the ground through manipulation of firsthydraulic cylinders and a crop gathering attachment mounted on a frontside of said crop feeder device, said crop gathering attachmentincluding fixed height sensors for measuring a distance of theattachment above the ground, said height sensors being connected via acontroller to said first hydraulic cylinders for the controlling theheight of said crop feeder device and said crop gathering attachmentmounted thereto, the improvement comprising: said crop gatheringattachment being mounted on a first axle carried by said crop feederdevice, said first axis being arranged horizontally and transversely tothe direction of travel of said crop harvesting machine so that saidcrop gathering attachment can title about a defined angle of tiltrelative to said crop feeder device; a second hydraulic cylinderpositioned between said crop feeder device and said crop gatheringattachment to control the angle of tilt of said crop gatheringattachment relative to said crop feeder device with a defined range,said second hydraulic cylinder being operatively connected to saidcontroller; a third hydraulic cylinder operably connected between saidcrop gathering attachment and said crop feeder device to rotate saidcrop gathering attachment about a generally horizontal second axisextending in the direction of travel; a tilt sensor for monitoring theangle of tile, said tilt sensor being connected via the controller tosaid first and second hydraulic cylinders to vary said angle of tilt;and the height sensors also being connected via the controller with saidfirst and second hydraulic cylinders to vary the angle of tilt.
 2. Thecrop harvesting machine of claim 1 wherein said tilt sensors are coupledwith mechanical feelers sliding on the ground, said mechanical feelersbeing movable as said height of said attachment varies.
 3. The cropharvesting machine of claim 2 wherein said crop gathering attachmentincludes a crop engaging apparatus located at a forward position on saidattachment, said mechanical feelers extending forwardly of said cropengaging apparatus.
 4. The crop harvesting machine of claim 3 whereinsaid crop engaging apparatus is a crop cutting mechanism.
 5. The cropharvesting machine of claim 3 wherein said crop engaging apparatus is acrop collection device including a pick up drum, said mechanical feelersextending forwardly of said pick up drum.
 6. The crop harvesting machineof claim 4 further comprising stem dividers located adjacent side wallsof the cutting mechanism and extending forwardly of said cuttingmechanism, said stem dividers being operatively associated with saidheight sensors for measuring the distance.
 7. The crop harvestingmachine of claim 1 wherein the defined range for the angle of tiltbetween the crop gathering attachment and the crop feeder device isapproximately 10 degrees.
 8. The crop harvesting machine of claim 1wherein said third hydraulic cylinder is associated with saidcontroller.
 9. The crop harvesting machine of claim 8 wherein thecontroller is a software controller connected to a set value transmitterfor defining a set distance of the crop gathering attachment above theground, the height sensors which continuously measure the actualdistance of the crop gathering attachment above the ground, and the tiltsensor for monitoring the defined range of the angle of tilt, saidcontroller controlling the operation of the first hydraulic cylinders ofthe crop feeder device, to the second hydraulic cylinder between thecrop feeder device and the crop gathering attachment and to the thirdhydraulic cylinder for rotating said crop harvesting attachment aboutsaid second.
 10. The crop harvesting machine of claim 9 wherein thecontroller is connected with an operating unit for inputtingpre-selected options relating to the operation of the crop gatheringattachment, said operating unit including at least one pushbutton formanual control, a second pushbutton for high cutting operation, a thirdpushbutton for regulating supporting pressure in said hydrauliccylinders, and a fourth pushbutton for engaging an operation to makesaid crop gathering attachment follow ground contours.
 11. The cropharvesting machine of claim 9 wherein the controller is provided with ahand lever for manual control of said crop gathering attachment.
 12. Thecrop harvesting machine of claim 9 wherein said controller calculates amean actual distance of the crop gathering attachment above the groundfrom the actual distances of the height sensors, said mean actualdistance being a control signal for the second hydraulic cylinder forreadjustment of the set distance, so long as the angle of tilt is withinthe defined range.
 13. The crop harvesting machine of claim 12 whereinthe signal from the tilt sensor monitoring the defined range of theangle of tilt becomes the control signal for the first hydrauliccylinders of the crop feeder device for readjusting into the definedrange with simultaneous adherence to the set distance for the cropgathering attachment above the ground when said angle of tilt attains orexceeds the upper or lower limits of said defined range.
 14. The cropharvesting machine of claim 13 wherein, for setting an initial positionof the crop gathering attachment for ground copying, the signal from thetilt sensor monitoring the defined range for the angle of tilt is thecontrol signal for the second hydraulic cylinder for readjusting theangle of tilt to a mean value, and the mean actual distance of the cropgathering attachment from the ground calculated by the controller is thecontrol signal for the first hydraulic cylinders for the feeder devicefor setting it to the set distance.
 15. The crop harvesting machine ofclaim 14 wherein the difference from actual distance of the cropgathering attachment above the ground is the control signal for thethird hydraulic cylinder which tilts the attachment about the secondaxis pointing in the direction of travel.
 16. The crop harvestingmachine of claim 9 wherein the height sensors for distance and the tiltsensor for monitoring the defined range for the angle of tilt are formedas angular sensors.